An emotional Mark Levy has paid tribute to Bob Montgomery, who unexpectedly passed away aged 82—just hours after he and his grandson Tom completed a 5,300-kilometre cross-country cycle to raise funds for motor neurone disease (MND).

The pair raised over $85,000 on their six-week journey, cycling from Broome, WA to Bowral, NSW, in honour of one of Bob's cousins who battled the condition.

Only a little over a month ago, Bob and Tom were in the 2GB studio to talk about their cross-country ride.